1. Field of the Invention
This invention lies in the field of valves actuated by stem movements and particularly to combination of such valves with preassemblable independent removable hermetic external seal means.
2. Description of the Prior Art
In the art of the aerosol-type valves, it is common for a reclosable valve assembly to be operated during opening and closing by means of the movement of the valve stem through application thereto of an appropriately applied external force, as from an operator's finger. Typically during operation, such a valve stem is moved or displaced (e.g., tilted or reciprocated) relative to its normally upright closed (typically axially aligned) position.
Especially when the fill of a pressurized container that is functionally associated with such a valve assembly (as the dispensing means) is sensitive to, or reactive with oxygen, water vapor, or other substances found in the atmospheric environment, it would be desirable, and for certain fills actually necessary, to seal externally and hermetically the valve assembly (relative to the fill in the container) until such time as the fill is to be dispensed and used. Further, when, for example, a bottom filled container is desired to be associated functionally with an externally hermetically sealed preassembled valve assembly wherein such seal is removable before fill dispensing, it would be necessary to employ a valve assembly which can be preassembled with the external seal in place, thereby to avoid associating an external seal with a valve assembly after the valve assembly is installed on its container. Thereafter, when a fill is being dispensed, such hermetic seal is opened (ruptured) permanently by means externally applied force after which the reclosable valve assembly can be opened and closed in typical (normal) fashion for dispensing the fill. Optionally, the external seal may be mechanically reassociated with the valve assembly to provide protection of the valve assembly against exteriorly originating bumps, etc.
In the prior art, a variety of externally used valve protective cover means have been employed to adjoin mechanically a protective member with a valve body. Such mechanical means have generally involved snap or force fits, screw-on arrangements, frictional fits, and like mechanical association. For example, one class of such protective cover means comprises so-called tamperproof closures. So far as can be presently determined, in such prior art, there are no true teachings or suggestions of using a separate bonding means to secure a protective cover over a valve for the purpose of providing a hermetic seal over and about the valve components, with which the protective cover and the bonding means are in gas-tight association.
One prior art teaching (Gach U.S. Pat. No. 3,334,769) wherein an external plastic cap is bonded by a layer of adhesive to the dispensing container over the valve assembly. This cap is only installable after the valve assembly is mounted (crimped) on the dispensing container. The cap cannot be installed on the valve assembly prior to the installation of the valve assembly on the container so that in a container/valve assembly composite assembly operation an extra step is required to install the cap on the composite. For reasons of manufacturing cost and convenience, it is cheaper and more efficient to preassemble an external seal with a valve assembly before the valve assembly is assembled with a container. Moreover, the sole function of the Gach cap is to prevent pilfering or the like and no teaching of a true hermetic seal is provided.
There is a need in the aerosol valve trade for an aerosol container manufacture to be able to buy his supplies of containers and valve assemblies in respective preassembled conditions, as those skilled in the art appreciate.
Thus, so far as is now known, reclosable valve assemblies of the type operatable by valve stem movement have not previously been known which were provided with removable external hermetic seal means wherein a seal means is bonded in a gas-tight manner to a valve body and wherein the seal means is preassemblable with the valve assembly before the complete valve assembly is assembled with a container to form the desired composite structure.
Previously, I have invented a class of reclosable valves operated by valve stem tilting which are provided with an external reclosable valve stem tip seal which is operated by valve stem tilting. This tip seal forms a second seal which protected material possibly retained in the stem from atmospheric action associated with valve stem tilting in a previous use; see Beard U.S. patent application Ser. No. 394,517, filed July 2, 1982, now U.S. Pat. No. 4,418,847. However, because this tip seal is operated through the existence of an internal force, it does not provide a hermetic seal of the class presently provided.